1. Field of the Invention
The present invention relates to a solid-state image pickup device and a camera system using the same, and particularly to an X-Y address type solid-state image pickup device which is represented by an MOS type solid-state image pickup device, and a camera system using the solid-state image pickup device as an image pickup device.
2. Description of the Related Art
As an X-Y address type solid-state image pickup device such as an MOS type solid-state image pickup device, an image pickup device including many unit pixels arranged in a matrix form has been known, each unit pixel being constructed by three transistors. FIG. 4 shows the construction of each unit pixel of the above image pickup device. As is apparent from FIG. 4, each unit pixel 100 comprises a photodiode (PD) 101, a transfer transistor 102, an amplifying transistor 103 and a reset transistor 104.
According to an MOS type solid-state image pickup device using the above pixel array, the potential of a floating node N101 is set to low level (hereinafter referred to as “L level”) on the basis of a signal input from a drain line 105 through the reset transistor 104 during a non-selection period for which a line is non-selected, and the potential of the floating node N101 is set to high level (hereinafter referred to as “H level”) when the line is selected.
As described above, in the conventional MOS type solid-state image pickup device including unit pixels each of which comprises three transistors, the potential of the floating node N101 is set to the L level (0V) during the non-selection period, so that electrons may leak from the floating node N101 into the photodiode 101, resulting in occurrence of noises.